Conventionally, clients in OTN networks can be any of multiple protocols and signal rates. The subtending client equipment may be specific processing equipment (switches, routers, Synchronous Optical Network (SONET) or Synchronous Digital Hierarchy (SDH) network elements, etc.) or other transport networks. Additional resiliency of the OTN client equipment/subtending client equipment/network handoff can be provided with a protected signal from that subtending equipment. OTN is defined in, for example, ITU-T Recommendation G.709 (12/09) “Interfaces for the Optical Transport Network (OTN)”, ITU-T Recommendation G.798 (10/10) “Characteristics of optical transport network hierarchy equipment functional blocks”, etc. Disadvantageously, OTN equipment may not have the capability to interwork with client specific protection schemes since it may be only mapping the client signals into OTN payloads rather than participating in the client protocol. Any such ability to participate in a protection scheme may be limited to the OTN monitoring, termination and generation capability of the OTN equipment.
Conventional systems and methods rely on participation in the client protocols to provide client-specific protection schemes. The conventional systems and methods which participate in client specific protection protocols require that client interface equipment terminate incoming client protocols and participate in those protection protocols. An example would be 1+1 Automatic Protection Switching (APS) protection for redundant SONET clients, where it would need to understand the APS byte signaling for the protection protocol. If the client interface equipment is remotely located and is using a protection protocol, OTN networking equipment may need to terminate the OTN layer in order to participate in that protection protocol whereas normally it would just perform an Optical channel Data Unit (ODU) connection function. Alternatively, if the client interface equipment is using an OTN based protection protocol, then the OTN networking equipment would need to participate in that APS protection scheme at the ODU connection point. This may be more difficult if the OTN line rate to the remote equipment is higher than the ODU connection rate, therefore requiring multiplexing to occur at the OTN networking point.
Additionally, the client protection scheme would only be able to be closed on the local equipment where the client signals enter the OTN network. The redundant client interfaces need the ability to compare signal status and communicate protection protocol requests. So it is not possible to have the protection scheme enter the OTN network on diversely located equipment, nor can the equipment which closes protection be remotely located from any of the equipment with the client interfaces.